Ultrathin Nitrogen‐Enriched Carbon Cover‐Enhanced Stability and Wettability of Au Nanocrystals on Core‐Shell Fe3O4@N‐Carbon Particles for Heterogeneous Catalysis

Abstract

AbstractWe report a core‐shell Fe3O4@nitrogen‐doped carbon@Au@nitrogen‐doped carbon (Fe3O4@N‐Carbon@Au@N‐Carbon) nanocatalyst based on a combined strategy, layer‐by‐layer deposition of aminophenol‐formaldehyde (APF) resin and subsequent pyrolysis. Isolated Au nanocrystals were sandwiched between ultrathin nitrogen‐enriched carbon cover and core‐shell Fe3O4@N‐Carbon. Transmission electron microscopy, X‐ray diffractor, X‐ray photoelectron spectroscopy, and other analysis methods were used to characterize the catalyst. Ultrathin nitrogen‐enriched carbon cover could stabilize Au nanocrystals, enhance their wettability with liquid polar organic substrates, and offer a relatively short transfer route of substrates towards active Au sites during catalytic transformations. For the reduction of 4‐nitrophenol, 2‐nitrophenol, 4‐nitroaniline and 2‐nitroaniline, the catalyst exhibits corresponding high turnover frequency of 378, 522, 834 and 846 h−1, respectively. The catalyst also shows high stability over 20 cycles almost without obvious structural damage and activity loss for reduction of 4‐nitrophenol.